Process of coating cement pipes



- v 1,61 ,540 Feb. 1927' E. LIGONNET 8 PROCESS OF COATING CEMENT PIPES Filed April 15. 1924 Jnueflfor' Eli/gourmet lf fys.

Patented F eb. 22, 1927.

UNITED STATES EUGENE neomrn'r, or rams, FRANCE.

rnocnss or eoarme CEMENT PIPES.

Application filed April 15, 1924, Serial no;

My present invention relates to a process of obtainingthe adherence by centrifugation of water tight coatings formed with asphalt, bitumen, asphaltic concrete, tar, pitch and the like to the inner walls and the ends of pipes and other cylindrical or conical members of cement, reinforced or not, and cen trifugated or not.- The process consists in forming by centrifugation inside the member to be coated a surface provided with asperities serving to cause adherence of said coatings.

The accompanying drawingillustrates diagrammatically in axial section an apparatus for performing the process. In a suitable cylinder a driven by'rollers b or any known means, an ordinary pipe 0 is placed. The pipe may be formed of concrete reinforced if desired. When assembled in this manner there is introduced into said pipe a mortar the volume of which is determined by the. area and thickness of the layer desired, said mortar being composed of sand, cement (more especially molten cement) and light materials such as pumice-stone, volvic, slag, coke or the like. Molten cement is a product" obtained by diffusion of clay in an electrical furnaceor of chalk CaO and bauxite and has the following formula-z This cement is an aluminous cement obtained by electrical treatment (see Reclferches industrielles sur les chaux, ciments et n'lortiers page 157 byL Bied, 1926, edited by Dunod, 92 Rue Bon a rte, Paris). Said' mortar is centrifugated' against the walls of the pipe which are still fresh. .Aftercentrifugation I obtain an inner wall provided with a layer of asperities f formed by the light materialsbut covered with a fine milk of cement. i

- As-a modification of this phase of the process, I may, after centrifugation of the pipe proper, introduce intd it during rotaftion a load of pebbles or other dense ma- 706,790, and in France February 27, 1924.

'or a powerful spray'of water-so as to remove the milk of cement.

The pipe is then mounted on the centrifugating device leaving a space of about a quarter of an inch, limited by a ring at the thickness of which isan inch or two greater than the thickness of the pipe.

t The pipe is heated inside by any suit able means. As soon as the desirable temperature is obtained, I introduce a volume of hot asphalt, bitumen, pitch or other material mentioned above, which volume is determined by the surface-and thickness of the coating required, then I centrifugate said material. The ends and inner walls are covered with a coating 6 and the watertight material penetrates into the asperities of the pipe and is anchored thereto. A current of cold water is sent into the pipe and when the temperature of the latter is sufliciently low the operation is ceased. The

adherence of the asphalt, bitumen, asphaltic concrete, pitch or the like is complete. 1

My process may also be employed with any other plastic material such as rubber, clay, etc.

What I claim is 1. A process of coating pipes and the like consisting in applying by centrifugation layer of material to formv asperitles in said layer, heating said pipe, andapplying an interior coating of bituminous material to" said pipe by centrifugation while said pipe is in a heated condition.- y

. 2. An improved pipe including a cementitious bodyfa layer of mortar containing, light divided,materials applied to the inner surface of the body so as to leave a series of asperities on the inner surface, and a coating of plastic material containing a bituminous substance applied to the first layer.

'In testimony signature.

whereof I hereunto aflin my EUGENE LIGO-NNET. 

